Reactive ion etch (RIE) is commonly used in the fabrication of integrated circuits. RIE generates reactive plasma which is used to remove materials deposited on a wafer. However, plasma processes, such as RIE, can undesirably cause plasma induced damage (PID).
FIG. 1 illustrates plasma induced damage (PID) resulting from a plasma process. As shown, a gate conductor 130 is formed on a substrate 105. The gate conductor includes a gate electrode 135 over a gate oxide 138. RIE is used to etch a contact opening 155 in a dielectric layer 158 to expose the gate conductor. Charged particles 190 generated from the RIE process penetrate through the gate electrode and are trapped in the gate oxide. These trapped charges can cause performance variations, compromising gate oxide integrity and leading to poor process capability (as measured by Cpk).
From the foregoing, it is desirable to reduce PID in integrated circuits.